After the Seattle Seahawks' disappointing loss to the Atlanta Falcons in the divisional round of the playoffs last year, head coach Pete Carroll and general manager John Schneider knew they had work to do. The wide receiving corps needed a game-changer who could stretch the field, and the defensive line needed pure pass-rushers.

Lo and behold, the brain trust delivered. The organization traded two draft picks for Minnesota Vikings wide receiver Percy Harvin and signed two prolific pass-rushers in defensive ends Cliff Avril and Michael Bennett.

Even though the jury is still out on Harvin’s tenure as a Seahawk, Avril and Bennett have been godsends. The two pass-rushing phenomenons combined for 16.5 quarterback sacks, 27 quarterback hits and 67 quarterback hurries.

Furthermore, the analysts at Pro Football Focus (subscription required) respectively awarded Avril and Bennett with rush grades of plus-14.4 and plus-20.9. Based on the aforementioned numbers, it’s safe to say Seattle turned a weakness into one of its biggest strengths.

This, in turn, is exactly why the Seahawks’ pass rush will be the true X-factor in Super Bowl XLVIII.

Don’t get me wrong—Seattle's secondary, the "Legion of Boom," deserves all the credit in the world for the job it did this season, but the Seahawks wouldn’t be where they are today without their vaunted pass rush. It has been tested time and time again that the success of a team’s pass rush directly correlates with its success in the secondary.

Strong safety Kam Chancellor believes that sentiment as well, as he told Clare Farnsworth of Seahawks.com when he earned a Pro Bowl alternate nod in 2011:

It all starts up front. Those guys, they give you that pass rush so the quarterback has to get the ball out fast. Those guys take on all the big, heavy blocks for us when we made the tackles. So, I mean, it all starts up front.

Yet the Seahawks’ pass rush won’t have to worry about forcing Peyton Manning to get rid of the ball quickly. He already does that. On 676 regular-season dropbacks, his average time to throw from the pocket was 2.36 seconds. That was the league’s best mark.

Moreover, his quarterback rating with less than 2.5 seconds to throw was an astonishing 121.4. It’s also worth noting that Manning wasn’t sacked when he unloaded the ball in less than 2.5 seconds.

Nonetheless, just like any other signal-caller, the 16-year vet has an area of weakness in the pocket.

When he holds on to the ball for longer than 2.5 seconds, his quarterback rating dips 17.2 points, and his completion percentage falls to 64.1 percent (compared to 70.8 percent). This is good news for the Seahawks’ pass rush because the Legion of Boom has the ability to bump receivers off their routes and stick to them like glue.

Additionally, Seattle is extremely creative when it comes to forcing pressure with its front four. Defensive coordinator Dan Quinn is a former defensive line coach, so he knows a thing or two about generating a pass rush. He also knows how crucial it is to play to his defensive line’s strengths, as he told reporters at Media Day, via Bob Condotta of The Seattle Times:

We don’t want to, generally, go too far away. That is the balance, in terms of our different looks to compared to what we do really well. We never like to get too far away from that in terms of our style and our attitude and how we like to play. There certainly will be some different looks that we have during the week.

The mixed looks from Quinn’s unit should prove to be interesting, yet it’s evident he’s confident in his scheme and his front four’s unique style. The uniqueness comes with the multitude of packages used on a weekly basis.

The most effective package the Seahawks defensive line has exhausted this season is the “Nascar” package. This variation features three pass-rushers who have their hand in the ground and one who stands up at the line of scrimmage.

In this deviation, Avril lines up over the right tackle, Bennett lines up over the right guard, Chris Clemons lines up over the left tackle and Bruce Irvin lines up over the left guard in a stand-up position.

NFL Game Rewind
NFL Game Rewind

On this play against the San Francisco 49ers, Avril took a speed-rush approach against Anthony Davis, Bennett utilized the rip move versus Alex Boone and Clemons tried a spin move on Joe Staley. Clemons ended up getting stonewalled, while the other two pushed the pocket and forced Colin Kaepernick off his spot.

As Kaepernick drifted to his left, Avril’s speed helped him dip under Davis’ attempted block. Once he scooted past the tackle, he closed on Kaepernick and forced a fumble. Bennett subsequently picked the ball up and rumbled down the sideline for 17 yards.

Avril’s closing speed around the edge was impressive, but Bennett’s ability to effectively exploit a matchup and win at the point of attack was even more impressive.

If the Seahawks plan to utilize this pass-rush package on Sunday, Bennett will have to bring his A-game when he's at defensive tackle. He will be taking on All-Pro right guard Louis Vasquez. Vasquez hasn’t surrendered a quarterback sack all season long. In fact, he has only allowed 14 quarterback pressures total.

As far as Avril goes, he will be squaring off against right tackle Orlando Franklin. Like Vasquez, Franklin is a sound pass-protector. Nonetheless, he has been flagged for his fair share of penalties this season. According to NFLPenalties.com, seven of his 11 penalties have been holding calls.

Broncos T Orlando Franklin said he gave up two sacks to Michael Bennett his rookie season. Well aware of Seattle's pass rush.

Even if Avril doesn’t garner a quarterback sack, he has the opportunity to make his presence felt by drawing a holding penalty on Franklin.

Clemons, on the other hand, has the "easy matchup." He will be testing his collection of pass-rushing moves on left tackle Chris Clark. Clark was an undrafted free agent in 2008, and 2013 has proven to be his first full season as a starter. His lack of experience could easily explain some of his pass-protection woes.

In 728 pass-block snaps (playoffs included), Clark has yielded seven quarterback sacks, six quarterback hits and 23 quarterback hurries. Clemons may not be the same player he once was, but that’s OK because he is still productive enough to work over Denver’s weakest link in pass protection.

The second variation (no particular order) of the Seahawks' “Nascar” package stays true to the New York Giants' original “Nascar” package. It features four down linemen. Avril is typically over the right tackle, Bennett is over the center, Clemons is over the left guard and Irvin is over the left tackle.

NFL Game Rewind
NFL Game Rewind

On this second play against the Arizona Cardinals in Week 7, the Seahawks' front four flushed quarterback Carson Palmer out of the pocket for a short gain. Irvin caved in the left side of the line when he bull-rushed the left tackle, Clemons collapsed the interior portion of the line with a bull rush and Avril deflated the right side of the line with a bull rush as well. Bennett was the only defensive lineman who didn’t manufacture a strong push.

Yet you can’t expect every rusher to beat the opposition on every play. If that was the case, the Seahawks’ pass rush would be more potent than it already is.

One shouldn’t expect to see Seattle’s “Nascar” package on every passing down. Why? Because it’s not designed to be an every-down defense. Quinn is keen on keeping his defenders fresh, which is exactly why we see so many different defensive line combinations.

A couple of the other players who have made an appearance in the “Nascar” package are defensive ends O’Brien Schofield and Benson Mayowa. Both players' snaps fell off in a big way after Irvin returned from his four-game suspension.

Sam Sharpe-USA TODAY Sports

As much as I like the Seahawks' base defense that often features defensive tackles Brandon Mebane and Clinton McDonald, it doesn’t hold a candle to the “Nascar” package. To beat the greatest quarterback in NFL history, Seattle must do a few things. The Seahawks have to force Manning into holding the ball for 2.6 seconds or longer, and they have to stay disciplined on play-action fakes and screens.

Finally, Seattle needs to throw in a blitz every now and again. Despite the fact the Seahawks rarely blitz, it would be wise to send a couple timely ones.

The most impressive pass-rusher who doesn’t play on the defensive line is middle linebacker Bobby Wagner. Wagner had five quarterback sacks, three quarterback hits and three quarterback hurries on 52 blitzes in the regular season.

Those are fairly sufficient numbers based on his low attempt totals.

Wagner can’t take all the credit for his achievements as a blitzer, though. The Seahawks defensive line does him plenty of favors when commanding double-teams. Take a look at the play below:

NFL Game Rewind
NFL Game Rewind

As you can see, Seattle’s defensive line slanted down toward the left side of the line. The subtle slant forced some odd blocking scenarios. The Tampa Bay Buccaneers left tackle and left guard doubled defensive end Red Bryant, the right tackle and the right guard doubled defensive tackle McDonald and the center handled Mebane.

Based on the fact Tampa Bay doubled an interior rusher and a defensive end, the backside blitz proved to be wide open. Irvin took the longest rush lane, and Wagner took the inside rush lane. After Wagner’s free run at Mike Glennon, he pulverized him into the turf.

What can’t the Seahawks’ pass rush do? It seems like they can do everything. Aside from getting after the quarterback, they can turn their peers on the defensive side of the ball into better pass-rushers by eating up blocks and making the appropriate calls and line shifts.

However, sacking Manning won’t be as easy as sacking Kaepernick and Glennon. Quinn’s pass rush will have to be perfect in its approach. That’s precisely why the pass rush will be the true X-factor.

If the pass rush doesn’t succeed, Sunday’s loss will fall squarely on the front four and their inability to get after Manning. But if the pass rush does succeed, Sunday’s win will be credited to the Seahawks' front four.